Last night the Welsh beauty, who is married to Michael Douglas, spoke of her ambitions for the appeal.
She said: "My childhood in Wales was a very happy one. However, I know that not all children are so lucky and I therefore want to do all I can, especially as a parent myself, to help keep them free from harm.
"Wales is still my home and I am delighted to be part of the NSPCC's very important work across the country."
The Welsh beauty, whose latest movie Entrapment 2 is about to hit the big screen, is joining the appeal's all-Wales Board.
Chairman of the appeal in Wales, Stanley Thomas, said: "Catherine will be a key support to the board's work and with her help we can go forward to achieving our goal of creating a society where all children are loved, valued and able to fulfil their potential."
In Wales alone it costs the NSPCC almost £3.5m to deliver their services.
The society runs 17 different operations across the country, including a Young Witness scheme.
* You can call the NSPCC Cymru/Wales Helpline on 0808 100 2524 from 10am to 6pm Monday to Friday.